Cluster Message Mismatch

CLUSTER MESSAGE MISMATCH

Theory of Operation

When powered, the Occupant Restraint Controller (ORC) broadcasts the Airbag Lamp On and Off request message on the Bus one time each second. In turn, the Cluster broadcasts the Airbag Lamp On or Off status message on the Bus one time each second. The Instrument Cluster controls the lamp based on the ORC message except during the bulb check. During the bulb check the Instrument cluster software forces the lamp on for 6 to 8 seconds regardless of the ORC bus message. The ORC does not monitor this DTC during the bulb test. The ORC will set this DTC if the ORC Lamp request message does not match Cluster Lamp status message for 2 seconds.

- When Monitored:
With the ignition and the Instrument Cluster (MIC) bulb check completed.

- Set Condition:
The ORC compares the request message and the status message and will set this DTC if they do not match for 2 seconds.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Restraints System Pre-Diagnostic Procedure.

1. DETERMINE ACTIVE OR STORED DTC

NOTE: Ensure that the battery is fully charged.

1. Turn the ignition on.
2. With the scan tool, read active ORC DTC.

Select ACTIVE or STORED DTC:

ACTIVE DTC

- Go To 2

STORED DTC

- Perform the RESTRAINTS SYSTEM INTERMITTENT TEST. Restraint System Intermittent Test.

2. CHECK FOR ACTIVE CLUSTER DTC
1. With the scan tool, read active Instrument Cluster (MIC) DTC.

Does the scan tool display any DTC?

Yes

- Perform the appropriate Instrument Cluster procedure. Testing and Inspection.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 3

3. VERIFY THAT THE AIRBAG LAMP REQUEST AND STATUS MESSAGE MISMATCH
1. With the scan tool, select the AIRBAG INDICATOR STATUS (OK, OPEN, SHORT).
2. Turn the ignition off, wait 15 seconds, then turn the ignition on.
3. Observe the AIRBAG INDICATOR STATUS during the Cluster bulb check and for 10 seconds afterwards.
4. Compare the Airbag IND REQ BY ACM status and the Airbag IND ON BY MIC status which display as either ON or OFF.

Do the IND status messages match within one second after a change in status?

Yes

- WARNING: Turn the ignition off disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
WARNING: If the Occupant Restraint Controller (ORC) is dropped at any time, it must be replaced. Failure to take the proper precautions could result in accidental airbag deployment and serious or fatal injury.

- Replace the ORC.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.

No

- Replace the Cluster.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.